1. Field of the Invention
The present invention relates to rotators for mixing materials for incubation and, more particularly, to rotators and shakers capable of receiving sealed bags containing, for example, membrane blots.
2. Related Art
Membrane-based assays are used for the analysis of nucleic acid and/or protein samples. These membrane based assays are called "membrane blots" or simply "blots" and include immuno blots (Western blots), Southern, and Northern blots. These blots are either stained with a specific dye and/or probed with antibody and/or nucleic acid probes. In order to successfully probe a blot, the blot must be agitated prior to incubation.
More specifically, blots are made by transferring electrophoretically separated protein and nucleic acid mixtures onto membranes with high binding capacity such as nitrocellulose or Immobilon-P (by Dupont). After proteins and/or nucleic acids are transferred from the gel matrix to a membrane, the blot is an exact replica of the original electrophoretogram. The blot is then either stained with a specific dye and/or probed with antibody and/or nucleic acid probes.
Practically speaking, probing a membrane blot involves placing the membrane into a sealable plastic bag (like a Seal-a-Meal.TM. bag) which is filled with a probe diluted in an incubation buffer. The bags are heat sealed before incubation and washing. The sealed bags containing blots soaking in an incubation mixture usually then require regular shaking (agitation) to assure even exposure of the membrane to the probe and to diminish unspecific binding of the probe to the membrane.
Agitation is usually accomplished by gently shaking the bag every few minutes or by placing the bags on a mechanical shaker or rotator. Unfortunately, prior art rotators and shakers are unsatisfactory for receiving the relatively large and flexible plastic bags containing blots. Indeed, prior art rotators and/or shakers are specifically designed for receiving test tubes for agitation, not blots.
Accordingly, there is a need in the art for a new rotator and shaker which is capable of receiving and agitating a blot for incubation which does not suffer from the disadvantages of the prior art designs.